Asphalt emulsions for treatment of coal and method of preparing the same



"a continuation-in-part.

Patented Dec. 2, 1947 COAL AND METHOD ORPREPABING THE SAME Charles namnmme, Plttsbnrg, m. aasignor oi ili'ty per cent to Joe I. Klaner, In, Pitts- J no Drawing. Application March 21, 1944, j

Serial No. 527.482

6 Claims. (01. 106-210 1 The invention relates to a colloidal suspension of asphalt which when sprayed on coal forms a permanent coating rendering the coal substantially dust-proof and imp rvious to moisture and oxidation, the present subject matter involving improvement over the subject matter or my copending application Serial No. 367,282, filed November 26, 1940, for Fuel and process of producing the same, of which the present applicationis An important object of the invention is to provide a substance of the character indicated which does not require to be heated for application to the coal, and which while forming a hard, dry, and permanent coating on the coal. does not cause the coal particles to objectionably adhere together.

Another important object of the invention is to provide an asphaltic coating for coal of the character indicated, which although of microrespect to other objects or materials with which 30 the coated coal may come into contact.

By "coal" as referred to herein. is meant bituminous, semi-bituminous, anthracite, semianthracite, or the so-called lignite coals, and others comprehended by these terms. The examples given hereinbelow as embodiments oi the invention will be understood to be exemplary only and as not restricting the invention except as defined in the appended claims.

In preparing the desired colloidal suspension of asphalt which is to be sprayed on the coal for the purposes set forth above, it is necessary to use asphalt of low initial penetration andhigh melting point of from 140 to 180 F., having certain characteristics. However, all such asphalts are not suitable. Some, for instance, do not exhibit the required ductility and adhesiveness to the coal, as Judged by the coating they form on the coal. but are unduly brittle and chip or flake oil the coal. Others, although providing suflicient ductility, produce excessive tackiness which causes the coal particles to stick together undesirably. For this reason processing of the asphalt as disclosed hereinbelow is essential to provide asphalt in the required form.

The source in the asphalt used is not critical and asphalt derived by the distillation oi crude oil and having an initial or original penetration range of 80 to 100 or 8 to 10 mm. and ductility between 150 to 180 or to 18 mm. has been found suitable and efficient.

In processing the selected asphalt, it is placed in an oxidizing chamber, where it is'heated, according to the rapidity of oxidation, to a temperature of from 140 to 180 F., and 'blown" with approximately 4000 cubic feet of air per minute, for about eight hours. This reduces the penetration of the asphalt to about 26 to 30 or 2.6 to 3.0 mm. and raises its melting point to about from 210 to 260 Fahrenheit.

The resultant asphalt is then'heated in a container to a temperature of about 300 Fahrenheit and run into the intakeof a colloid mill simultaneously with an approximately equal amount by volume of the aqueous dispersion which is described below and which has been heated in a separate container to a temperature of about 180 Fahrenheit. The resultant emulsion is discharged into a heat exchanger by which its temperature is rapidly reduced to about 150 Fahrenheit, whence the emulsion is run into storage containers.

The said dispersion consists of the following components in substantially the proportions, by volume, set forth:

. Per cent Water 95.04 Resin (a. substantially petroleum hydrocarbon insoluble pine wood resin) 3.00

Bentonite clay s 1.40 Tall i .10 Caustic soda 0.46

It is to be noted that the asphalt is heated to 300 Fahrenheit before being run through the colloid mill. This is necessary in order to bring the asphalt to a state of sufllcient fluidity to mix with the water component of the above dispersion and subsequently form a colloidal compound, but introduces a problem in view of the fact that the boiling point of water is 212 Fahrenheit. In order to overcome this problem it wasv found necessary to produce and maintain a constant and critical rate of flow while the combined ma- 50 terials are fed through the colloid mill, which depends upon the size of colloid mill used. In other words, the rate of flow is not in itself critical, but the speed of the mill is, and-the speed of the mill is the determining factor of the rate 55 o! flow. In using a colloid mill having a normal speed of 10,000 R. P. M. it was found necessary to reduce its speed to substantially 5,000 B. P. M. Otherwise the material obtained was found to be unsuitable for coating coal in accordance with the present invention. Any eificient heat exchanger can be-usedi'f the constant rate of flow throughthe colloidal mill is maintained and the speed of the mill is not permitted to go above about half normalspeed or, in the example given,

5,000 R. P. M.

The'resultant colloidal suspension of. asphalt does not need any special treatment and to be heated to render it usable after a long period of storage, unless it has been stored at a temperature below its freezing temperature of about 32 Fahrenheit, in which event it requires only sutflcient application of heat to restore it to a fluid and atomizable or sprayable condition. At 70 Fahrenheit the material has a viscosity of 18, as .compared with for water at the same temperature. v

The resin component of the above dispersion is identified as a gasoline insoluble resin obtained, for; example,:from pine wood by extractionof comminutedpine wood by a coal tar hydroearbon, removal offthe nixtureof solid resins, extracting such s'olid' resin 'mixturebyna volatile paraflln hydrocarbon to' removerosin from said resin mixture, and covering a:-;paraflin hydro-' carbon-insoluble resin substantiallyiree from rosin. Such a resin substance is disclosed and y claimed in Patent No. 2,193,026, granted March 12, 1940, to Lucius Coleman Hall,

The tall oil component of the abovedispersion disclosed in Patent No. 2,305,498 granted December 15, 1942, to Ernest Segessemann, is in general-the resinous and fatty by-product obtained chiefly in the production of paper pulp from resin-bearing woods by the so-called sulphate process. In the sulphate process wood is digested with an alkalineliquor containing sodium sulphate, during which process tall oil accumulates in theform of its sodium soap on the 'surface'of the waste liquor.

The coating material of the present invention,

' requiring no heating at above freezing temperatures, can be sprayed or atomized on the coal, directly from the storage containers, by means of any suitable spraying equipment, including such" as is used for spraying other coal coating fluids Having described the invention, what is claimed as new is:

1. The method of making a colloidal suspension of asphalt for spraying on coal at atmospheric temperature to form a permanent coating rendering the coal substantially dust-proof and impervious to moisture and oxidation, which consists in taking an asphalt of a type having initially a penetration rating of about 8 to 10 mm. and a ductilitywrating of about 15 to 18 mm, and blowing the asphalt at an oxidizing tempera ture of from 140 to 180 F. in an oxidizing chamber with about 4,000 cubic feet of air per minute for about eighthours to reduce the penetration of the asphaltto about 2.6 to 3.0 mm. and raising its melting point 'to about from 210 to 260 F., then heating the asphalt in a container to a temperature not over 300 F., then simultaneously running the hot blown asphalt through a colloid mill operating at substantially 5,000 P. M., and at a constant rate, together with an aqueous dispersion heated to about 180 F., said dispersion containing by volume substantially 95.04% of water, 3% of a substantially petroleum 1 4 H ,l -F:4 -gil, hydrocarbon insoluble pine wood resin, 1.4% of bentonite, 0.10% of tall oil, and 0.46% of caustic soda, then rapidly reducing the temperature of the resultant emlulsion to about 150 F., for storage. 1

2. Material'adapted'to be sprayed at atmospheric temperature on coal and forming thereon a hard, dry and permanent coating rendering the coal dust-proof, moisture-proof and oxidation-proof and preventing the same from becoming sticky and adhering to cause large lumps, consisting of a colloidal suspension of asphalt of a type having initially a low penetration and a high melting point after being heated and blown in an oxidizing chamber with approximately 4,000 cubic feet of air per minute for about eight hours and the penetration of the asphalt reduced to about 2.6 to 3.0 mm. and its melting point raised to about from 210 to 260 F., the resultant asphalt heated to a temperature of about 300 F. and simultaneously run through a colloid mill with an approximately ,equal amount by volume of an aqueous dispersion composed of water 95.04%, a substantially petroleum hydrocarbon insoluble pine wood resin 3.0%, bentonite clay 1.4%, tall oil 0.10% and caustic soda 0.46% at a temperature of about 180 F. and the resultant emulsion rapidly reduced to a temperature of about 150 F.

3. A method of producing a coating composition for coal for application as a spray at atmospheric temperature which consists in running a quantity of colloidal asphalt'derived by the distillation of crude 011 after havingbeen previously'heated in an oxidizing chamber to a temperature of from to 180 F. and blown with approximately 4,000 cubic feet of air per minute for about eight hours to reduce the penetration of the asphalt to about 2.6 to 3.0 mm. and raising its melting point to about 210 to 260 F. and then heated to a temperature of about 300 F., with an equal volume of an aqueous dispersion of the following ingredients in the proportions stated, consisting of water 95.04%, a substantially petroleum hydrocarbon insoluble pine wood resin 3.0%, bentonite clay 1.4%, tall 011 0.10% and caustic soda 0.46% and then discharging the resultant emulsion into a heat exchanger to rapidly reduce the temperature thereof to F.

4. A method of producing a coating composition for coal for application as a spray at atmospheric temperature, which consists in simultaneously running through a colloidal mill operating at substantially 5,000 R. P. M., a hardened colloidal blown asphalt having a penetration of about 2.6 to 3.0 mm. and a melting point of about 210 to 260 and heated in a container to a temperature of about 300 F., with an equal volume of an aqueous dispersion heated to a temperature of about 180 F. and containing by volume 95.04% water, 3.0% of a substantially petroleum hydrocarbon insoluble pine wood resin, 1.4% of bentonite clay, 0.10% of tall oil and 0.46% of caustic soda and subsequently rapidly reducing the temperature of the resultant emulsion to about 150 F.

5. An asphaltic coal coating composition consisting of a colloidal emulsion of blown asphalt of a type characterized before the blowing by low penetration and high melting point and run into the intake of a colloidal mill after being preheated to a temperature of about 300 F., simultaneously with an approximately equal amount by volume of an aqueous dispersion at a temperature of about 180 F. containing water 95.04 a substantially petroleum hydrocarbon insoluble pine wood resin substantially free from rosin 3.0%, bentonite clay 1.4%, talloil 0.10%, and caustic soda 0.46% and then rapidly reduced to a temperature of about 150 F.

6. A method of producing an asphaltic coal coating composition consistingin forming a colloidal emulsion of 50% by volume of hot blown asphalt heated to a temperature of about 300 F. and characterized by initial low penetration rating and high melting point to reduce the penetration and raise the melting point and simultaneously running the same at a constant rate of flow through a colloidal mill at a constant speed of substantially 5,000 R. P. M., with an approximately equal volume of an aqueous dispersion of approximately 50% by volume of the total emulsion consisting of water 47.52%, a substantially petroleum hydrocarbon insoluble pine wood resin 1.5%, bentonite clay 0.70%, talloil 0.05% and caustic soda 0.23% and then discharging the resultant emulsion into a heat exchanger to reduce its temperature to about 150 F.

CHARLES R. ROSENCRANSE.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,350,548 De Laney June 6, 1944 2,340,449 Barwell Feb. 1, 1944 2,314,242 Porter Mar. 16, 1943 2,256,886 Buckley Sept. 23, 1941 2,125,753 Spencer Aug. 2, 1938 2,016,306 Watts Oct. 8, 1935 1,884,919 Thompson Oct; 25, 1932 1,807,808 Symons June 2, 1931 1,734,437 Kirschbraun Nov. 5, 1929 FOREIGN PATENTS Number Country Date 471,650 Great Britain Sept. 8, 1937 263,307 Great Britain Dec. 30, 1926 252,260 Great Britain May 25, 1926 656,634 Germany Feb. 10, 1938 

